A material delivery can arrive exactly on its booked date and still arrive at the wrong time. The installation area may not be ready. A lifting slot may be missing. The drawing used for fabrication may no longer match the approved detail.
For a practical just-in-time approach, we suggest treating materials and information as two connected delivery streams. An installation package is ready only when both streams meet the needs of the people doing the work.
What just-in-time is trying to achieve
The Lean Construction Institute describes just-in-time as coordinating supply with demand so material arrives when needed, reducing unnecessary inventory and handling. Its construction application depends on coordination, not simply asking suppliers to deliver later. Source: LCI, Just-in-time.
Our interpretation for a live project is deliberately cautious: reduce avoidable waiting and storage, but do not confuse lean delivery with having no protection against uncertainty. A critical bespoke item with a long replacement lead time deserves a different buffer decision from a readily available consumable.
Pull the information dates back from installation
Begin with the installation sequence, then work backwards through the actual dependencies. Ask when the team needs approved information, when manufacture must be released, and when any submittal or coordination question must be resolved.
Consider this illustrative planning sequence, not a standard lead-time allowance:
| Relative milestone | Evidence needed before proceeding |
|---|---|
| Thirty working days before installation | Coordinated information available for the package’s agreed review |
| Twenty working days before | Fabrication release authorised, with revision and scope confirmed |
| Five working days before | Supplier readiness, unloading access and lifting arrangements reconfirmed |
| Two working days before | Material received, inspected and placed in the agreed location |
| Installation day | Workface, people, tools, permits and information confirmed ready |
These dates are invented to explain the logic. A real plan must use supplier commitments, review durations, inspection needs and the project calendar. Where approval is still outstanding, the procurement milestone is a constraint, not a green status because a drawing was uploaded.
Define a usable information package
Our suggested release check has four questions. Is this the correct location and scope? Is the revision current? Is its approval status suitable for the intended use? Does the receiving person know what changed?
A model, drawing or specification should have a clear purpose at each stage. “Available” might mean ready for coordination, ready for fabrication or approved for construction. Those are different promises. Put the intended use and required-by date in the information register rather than relying on a folder name alone.
When a revision changes an already released package, make the affected supplier and site owner part of the change check. Updating the document system without updating the material decision leaves a gap between the two streams.
Use a readiness conversation before a delivery booking
The Last Planner System includes making work ready by removing constraints, followed by reliable short-term commitments and learning from non-completion. Its planning logic includes the information and resources needed to execute work. Source: LCI, Last Planner System.
A compact weekly review can apply that logic to each upcoming package. We suggest reviewing information status, material status, access, preceding work and inspection requirements together. Give each missing prerequisite an owner and a date.
For example, “delivery confirmed” should not conceal “receiving inspection not arranged”. “Drawing issued” should not conceal “supplier still working to the previous revision”. The meeting should end with specific commitments and explicit constraints, not a list of reassuring colours.
Choose buffers rather than inheriting them
For each important package, consider the consequence of late delivery, replacement lead time, storage limits, damage risk and realistic transport uncertainty. Then agree where protection belongs: supplier capacity, an earlier decision, a small local stock, a temporary holding area or additional schedule allowance.
This is a risk-based recommendation, not a claim that any one buffer is universally correct. An early material delivery can obstruct another operation; a very late one can leave no recovery time. The useful question is which arrangement protects the installation sequence with the least unnecessary handling.
Learn from missed commitments
We recommend recording the reason when a planned installation does not happen: missing information, unavailable access, incomplete preceding work, supply delay or another defined cause. Review patterns rather than using the record to allocate blame in the daily meeting.
Distinguish the promised delivery date, actual receipt and actual installation. Those three timestamps tell different stories. Add the information release date and the story becomes more useful: a supplier may have delivered reliably after receiving a late instruction.
The goal is not a perfectly timed truck. It is a work package that can actually proceed.
Related reading: 4D planning beyond the animation and contractor–client conflict management.
